Change-gear device



v Se t.'17', 1929. G. BLACKSTOCK 1,728,325

CHANGE GEAR DEVICE Filed March 17, 1928 70/? a. BZHCKS Max HTTORNCYJ" Patented Sept. 17, 1929 i T UNETED STATES PATENT OFFICE GIBBS BLAOKSTOC'K, OF TORONTO, ONTARIO, CANADA CHANGE-GEAR DEVICE Application filed March 17, 1928. Serial No. 262,434.

My invention relates to improvements in ing 16 and lock the wheel and parts conchange gear devices, and the object of the innected thereto from rotation, the periphery vention is to devise means for automatically of the wheel at the'opposite side of the notch changing gear controlled by change in load opening being curved beyond the normal peand the speed of the engine, thereby relievriphery of the wheel as indicated at 19 so 5 ing the operator of work, eliminating noise that when the wheel is rotated counter clockand crash in gear changing, increasing to wise the spring pressed pawl 11 will be carhigher speed more easily and quickly, which ried over the opening 16 so that it will not will automatically change into low when engage the notch and lockthe wheel and o needed on ascending hills, and by which a parts connectedthereto from rotation.

quick get away'is provided in traffic, and it 20 is an internal stationary ratchet gear. consists essentially of the arrangement and 21 is a dog engaging therewith such dog beconstruction of parts as hereinafter more ing pivotally mounted as indicated at 22 on particularly explained. the annular gear 6. The dog 21 is provided 15 Fig. 1 1S a face elevation. of my device with a we1ght21 anda tension spring 21 by with the engine or drive shaft in section. which it is carried in and out of engagement Fig. 2 is a side elevation of the parts shown with the teeth of the annular ratchet'gear 20. in F ig. 1 the exterlor annular gear being 1n Having described the prlncipal parts insection. volved in my invention I will briefly describe 0 Fig. 8 is an enlarged detail of the locking the operation of the same. i

pawl and coacting parts. It is assumedthat all the parts are sta- Fig. 4 is an alternative construction of tionary and in their normal position. spring support for the weights. Upon starting the engine the engine shaft In the drawing like characters of reference 1 and gear 3 are rotated in thedirection of indicate corresponding parts in each figure. arrow or clockwise, and thereby rotating the 1 indicates the engine shaft and 2 the gear '1 in acounter'clockwise direction asindriven shaft. 3 is a gear secured to the en cheated by arrow. The shaft 5 to which the glue shaft. 1} is a disc secured to the driven gear 7 is secured is turned in the same direcshaft. 5 are short shafts mounted in beartioncarrying the wheel 15 and the weighted 3o ings 3 forming part of the disc 4. 6 is a arm 9, which is locked to the wheel by the floating ring provided with an annular inpawl 11, in the same direction, that is, internal gear. 7 is a gear mounted on each ward. By this action the free end of the shaft 5 and meshing with the gear 3 of the cam fin er 12 is carried against the projecengine shaft. 8 is a gear mounted on the tion 13 which is held stationary by the iner- 35 opposite end of each shaft 5 and meshing tia of the parts or the load. with the gear ring 6. 9 is a weighted arm The pressure of the finger 12 against the swung freely on each shaft 5 and in which is projection 18 swings the cam finger inward journalled a rocking shaft 10 on which is serocking the shaft 10 in the same direction cured a pawl 11. 12 is a cam finger also seand swings the pawl 11 which is also secured 4L0 cured to the shaft 10 and coacting with a cam to shaft 10 outward out of engagement with projection 13 carried by the disc 4' and the wheel 15 which is thereby freed. spring held thereagainst by a suitable spring It will be noted that the gear ring 6 is 14. 15 is a wheel having peripheral notches held stationary from moving in a counter 16 forming a shoulder 17' with which the clockwise direction by the dog 21 engaging 45 wl 11 engages. the ratchet 20. It will therefore be seen The periphery of the wheel is inclined inthat as soon as the wheel 15 is unlocked as ward towards the shoulder as indicated at 18 above described that the rotation of the so that when the wheel 15 is rotated clockgear 7, shaft5 and gear 8 which are one wise the spring pressed pawl 11 will be cargear unit will tend to force the gear 6 in a 50 ried into the notch through the notch opencounter clockwise direction, such movement being prevented by the dog 21 engaging the ratchet '20. The counter clockwise movement of the gear 6 being prevented, the gear 8 will in consequence when rotated travel in a clockwise direction around the internal gear of the gear ring 6 carrying the disc 4 in the same direction, and thereby transmitting motion to the driven shaft 2 to which the disc t is connected producing a reduced ratio or approximately a 2 to 1 ratio between the driving shaft 1 and driven shaft 2 or a low gear drive;

The speed of rotation carries the weighted arms 9 again outward into the position shown in the drawing, the pawl 11 travelling freely around the periphery of the .wheel 15 but spring pressed thereagainst.

In order to change from low to high gear the engine is slowed down. The momentum of the load maintains the speed of the driven shaft 2 and disc ,4. lVhen the engine speed reaches that of the driven shaft and tends to fall momentarily below it reverse rotation is given to the gear 7 and wheel 15 so that the end of the pawl 11 passes down the incline 18 into the notch 16 to engage the shoulder 17. p

The engine is then gradually speeded up the pawl remaining in its engaged position so that'the gear 7 shaft 5,wheel 15, gear 8, arm 9 and gear ring 6 are locked as one unit traveling with the gear 3 and shaft 1 so that the transmission shaft 2 is driven at engine speed from the engine shaft. The dogQl travels in a clockwise direction aroundthe ratchet gear 20 and is freed therefrom by centrifugal force acting on the weight 21".

Thechange from high to low gear occurs automatically when torque about the shaft 5 due to driving thrust is sufiicient, as say when climbinga hill, to overcome the opposing torque about shaft 5 due to the centrifugal action of the weighted arm Swhich is then swung inward and the pawl 11. released from the wheel15, freeing the gears 7 and 8 to operate as reducing gears between. the engine shaft gear 3 and gear ring 6. Y

Simultaneously the checking of the speed of they gear 6 causes the weight 21 by its momentum to travel inward and thereby carry the dog 21 into engagement with the ratchet 20 so that the mechanism operates at low or reduced gear as above described.

What I claim as my invention is 1. In a change speed device, the combination with the drive and driven shafts, of an external gear carried by the drive shaft, an

internal fioatinggear ring free to rotate in the direction of rotation of the engine shaft, a gear drive interposed between the external and internal gears and, "carried by the driven shaft, means for locking the gear ring from rotation in a direction opposite to the direction of the drive shaft, a weighted arm releasabl-y connected to the interposed gear drive tohold the gear drive stationary by centrifugal action, and means operated by increase of driving torque for releasing the connection between the arm and the interposed gear.

2. In a change speed device, the combination with the drive and driven shafts, of a gear secured to the drive shaft, an annular internal gear capable of rotation in one direction only, and gears interposed between the gear of the drive shaft and annular gear, a shaft carried by the driven shaft to which the interposed gear is secured, a notched in the direction of the drive shaft, of a reduction drive between said shafts comprising a gear connection carried by the driven shaft between the drive shaft and annulus, a latching device to posit vely hold the reduction drive from rotation, means operated by centrifugal action to maintain the latching device in engagement, and means for releasing the latch actuated by the torque generated in. the reduction drive adapted to re-engage by the reduction of the driving shaft speed approximately to the speed of the driven shaft.

l. In a change speed device, thecombination with a drive and driven shaft, and an internally geared annulusfree to travel only in the direction of the driving shaft, of a reduction drive between said shafts comprising a gear connection carried by the driven shaft between the drive shaft and annulus, a notched wheel rotating with such gear connection, a free weighted arm pivotally carried by such gear connection, a latch pawl pivotedupon the arm and held in engagement with the notched wheel by the arm as it is carried outward by centrifugal action, and means for releasing the pawl actuated by the torque on said gear connection adapted to re-engage as the speed of the driving shaft is reduced "approximately to the speed of the driven shaft.

c 5. In a change gear device, the combination with a drive and a driven shaft, and a reduction gear connect-ion therebetween, of a rotatable member driven from the drive shaft, driven member secured to the driven shaft, a radially movable weight carried on the driven member, a locking member carried by the weight, said locking member being held in positive engagement with the rotatable member to positively lock the drive and driven shafts together by the weight held outward by centrifugal action and means 00- acting with the inward movement of the weight due to load counteracting such centrifugal action for releasing the locking member, and re-engaging when the speed of the drive shaft is reduced to that of the driven shaft and a ratchet and dog controlled device against which the reduction gear reacts when the locking member is released from the rotatable member and against which reaction automatically ceases when the locking member engages the rotatable member.

6. In a change gear device, the combination with a drive and driven shaft, of a driving connection therebetween comprising a notched whee-l driven from the drive shaft, a pawl carrier secured to the driven shaft, a weight carried on the pawl carrier to move radially, a spring pressed pawl carried by the weight and coacting with the notched wheel and held in engagement by the weight held outward by centrifugal action, and pawl releasing means carried by the carrier and coacting with the weight to release the pawl as the weight is moved inward by the load counteracting the aforesaid centrifugal action and a ratchet and do controlled reaction member against which the reduction gear reacts when the pawl disengages the notched wheel and against which reaction automatically ceases when the pawl disengages the notched wheel.

7. In a change gear device, the combination with a drive and driven shaft, of a driving connection therebetween comprising a notched wheel driven from the drive shaft, a pawl carrier secured to the driven shaft, a weight carried on the pawl carrier to move radially, a spring pressed pawl carried by the weight and coacting with the notched wheel and held in engagement by the weight held outward by centrifugal action, and pawl releasing means coacting with e the weight to release the pawl when the weight is moved inward by the load as it counteracts the aforesaid centrifugal action, the pawl being adapted to re-engage by the reduction of the speed of the driving shaft to the speed of the driven shaft and a ratchet and dog controlled reaction member against which the reduction gear reacts when the pawl disengages the notched wheel and against which reaction automatically ceases when the pawl disengages the notched wheel.

8. In a change gear device, the combination with a drive and driven shaft and a reduction gear connection therebetween, of a notched wheel driven from the drive shaft,

a pawl carrier secured to the driven shaft.

a weight carried on the carrier to move radially, a spring pressed pawl carried by the weight and coacting with the notched wheel and held in engagement by the weight held outward by centrifugal action and pawl releasing means coacting with the weight to release the'pawlwhen the weight is moved inward by the load counteracting the aforesaid centrifugal action, said pawl being adapted to re-engage when the speed of the driving shaft is reduced to the speed of the driven shaft, and aratchet and dog controlled reaction member against which the reduction gear reacts when the pawl disengages the notched wheel and against which reaction automatically ceases when the pawl disengages the notched wheel.

9. In a change gear device, the combination with the drive and driven shaft, of a releasable direct drive connection between the drive and driven shaft comprising a rotatable member. driven from the drive shaft, a driven member secured to the driven shaft, a radially movable weight carried on the driven member, a locking member coacting with the weight adapted to engage the 170- tatable member whenthe speed of the drive shaft is reduced to that of the driven shaft and to be held in engagement by the weight held outward by centrifugal action to positively lock thedrive and driven shafts together, means for releasing the locking member when the weight moves inward owing to the counteraction of centrifugalaction by the load, and a reduetidn gear. connection comprising a gear secured to the drive shaft, an internally geared annulus free to revolve only in the same direction asthe drive shaft, and gears carried on the driven member between the gear on the drive shaft and the annulus. I

10. In a change gear device, the combination with the drive and driven shaft, of a re leasable directdrive connection between the drive and driven shaft comprising a notched wheel driven from the drive shaft and a driven member secured to the driven shaft,

a radially movable Weight carried on the driven member, a pawl coacting with the weight adapted to engage the notched wheel when the speed of the drive shaft is reduced to that of the driven shaft and to be held in engagement by the weight held outward by centrifugal action .to positively lock the drive and driven shafts together, means for releas ing the pawl when the weight moves inward owing to the counteraction of the centrifugal action by the load, and a reduction gear connection comprising a gear secured to the drive shaft, an internally geared annulus free to revolve only in the same direction as the drive shaft and gears carried on the driven member between the gear on the drive shaft and the annulus.

11. In a change gear device, the combina tion with the drive and driven shaft, of a driving connection therebetween comprising a notched wheel driven from the drive shaft, a pawl carrier secured to the driven shaft, a wei 'ht carried on thepawl carrier to move 1 radially, a spring pressed pawl coacting with the weight and with the notched wheel, engaging when the speed of the drive shaft is reduced to that of the driven shaft and held in engagement by the weight held outward by centrifugal action, pawl releasing means carried by the carrier coacting with the weight to release the pawl as the weight is moved inward by the load conteracting the aforesaid centrifugal action, and a ratchet and dog controlled re-action member against which the reduction gear re-acts when the pawl liengages the notched wheel and against which the re-action automatically ceaseswhen the pawl disengages the notched wheel,

12. In a change gear device, the combination with the drive and driven shaft. and a releasable direct drive connection therebetween, of a reduction gear system comprising a gear secured to the crive shaft, an internal floating ring gear, gears carried on the driven shaft between the ring gear and drive shaft gear, a fixed ratchet rack adjacent to the ring gear, and a spring pressed dog pivoted on the ring gear to engage the ratchetrack and prevent rotation of the ring gear in a direction opposite to the drive shaft, the aforesaid dog being so weighted that when the ring gear is in motion the dog is held clear of the ratchet rack by centrifugal action and when the ring gear is negatively accelerated the relative forward motion of the weighted part tends to force the point of the dog against the ratchet rack.

13. In a change gear device, the combination with a drive and a drivenishaft, and a low gear train ofthe planetary type provided with a floating reaction gear capable of rotation only in the normal forward direction of the drive shaft, of releasable means for directly connecting the drive and driven shafts together, comprising adjacent driving and driven members connected respectively with the drive and driven shafts and an interposed locking device to engage and lock such members together as the speeds of the shafts are equalizecha movable weight connected to the lockingdevice to hold it in engagement by centrifugal action, and means I for releasing the locking device actuated by inward movement of the weight due to excessive load on the drive shaft.

14:. In a change gear device of the type described, the combination with the drive and driven shafts, and a low gear drive th-erebetween, of a high gear drive in which is incorporated a releasable connection comprising, a driving member driven from the driving shaft and a driven member to transto form the low gear drive connectionbet-ween the drive and driven shafts;

15. In a change gear device, a reduction gear system, a floating reaction member incorporated in the reduction gear system, means for preventing the reverse rotation of the reaction member comprising an adjacent fixed member and a locking member on the reaction member so weighted that the weighted part tends by its centrifugal action to hold the locking member clear of the fixed member when in motion and by its momentum tends to carry the locking member into engagement with the fixed member when the reaction member is rapidly checked in motion.

GIBBS BLACKSTOCK. 

